The Met Police says 12 men have been arrested in connection with the apparent attempt to take control of a Santander Bank computer in order to steal money.
The 12, aged 23-54 years old, were detained in Hounslow yesterday (Thursday).
The property in Hillingdon borough, plus others in four other London boroughs and in Slough, were raided later.
The men are all still in custody, and the Met has released no further details so far.
Santander said in a statement today (Friday) that no money was ever at risk and any fraud that may have been attempted had failed and would never have been successful.
